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901.
A series of seven new 2′,3′,4′‐substituted spiro[isothiochromene‐3,5′‐isoxazolidin]‐4(1H)‐ones ( 7‐13 ) has been prepared in the reaction of benzylidene(phenyl)azane oxide ( 5 ) or benzylidene(methyl)azane oxide ( 6 ) with (3Z)‐3‐(4‐substituted‐benzylidene)‐1H‐isothio‐ chromen‐4(3H)‐one ( 1‐4 ). The reaction occurs by a 1,3‐dipolar cycloaddition mechanism that leads to the regiospecific formation of various spiroisoxazolidines ( 7‐13 ).  相似文献   
902.
The di- and triorganotin(IV) derivatives of anthracenecarboxylic acid, Ph2MeSnOC(O)C14H9 (2), Me3SnOC(O)C14H9 (3), Me2Sn[OC(O)C14H9]2 · CH3OH (4) Ph3SnOC(O)C14H9 · CH3OH (5), Ph2EtSnOC(O)C14H9 (6), Ph2Sn[OC(O)(C14H9)]2 (7) and PhMe2SnOC(O)C14H9 (8) were synthesized by the reaction of Ph2MeSnI, Me3SnCl, Me2SnCl2, Ph3SnCl, Ph2EtSnI, Ph2SnCl2, and PhMe2SnI with 9-anthracenecarboxylic acid, respectively, with the aid of potassium iso-propoxide. All complexes were characterized by elemental analysis, mass spectrometry, IR, 1H, 13C and 119Sn NMR spectroscopes. The molecular structures of complexes 2, 3 and 4 were determined by single crystal X-ray analysis. The X-ray structures reveal that complex 2 and 3 adopt a polymeric trans-C3SnO2 trigonal bipyamidal configuration with the oxygen atoms occupying axial positions. Complex 4 adopts a monomeric structure with two carboxylates coordinated to tin in a monodentate form from axial and equatorial positions, and with the coordination number raised to five as the methanol occupies the apical position of the trigonal bipyramid.  相似文献   
903.
Ring opening metathesis polymerization (ROMP) of bicyclo[2.2.1]hept‐2‐ene (norbornene) is carried out over silica‐supported catalysts based on tungsten complexes bearing an oxo ligand ( 1 : [(SiO)W(O)(CH2SiMe3)3, 2 : [(SiO)W(O)(CHCMe2Ph)(dAdPO)], dAdPO  2,6 diadamantyl‐4‐methylphenoxide, 3 : [(SiO)2W(O)(CH2SiMe3)2]). The evaluation of the catalytic activities of the aforementioned materials in ROMP indicates that at low reaction time (0.5 min), the highest polymer yield is obtained with catalyst 2 . However, for longer reaction time (>2 min), complex 3 , a model of the industrial catalyst, exhibits a better monomer conversion. The polymers obtained are characterized. Moreover, these catalysts are shown to be rather preferentially selective to give the cis polynorbornene (>65%), characterized by high melting points (≈300 °C). The experimental values of the average molecular weight (Mn) of polynorbornenes are found to be close to the theoretical ones for the polymers prepared using catalyst 2 and higher for those originated from catalyst 3 .

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904.
BACKGROUND: Using folktales we can find some aspects of social customs. Here, I show the situation of consanguineous marriages in folktales from different Iranian populations and try to compare it with the present situation of consanguineous marriages. METHODS: The study includes tales from 11 different Iranian (ethnic and/or geographical) populations. Overall, the records of 585 marriages in 296 folktales from the study populations were found. RESULTS: The estimated mean inbreeding coefficient (alpha) for different populations using folktale records is lower than that of the present values. However, there is a very high level of statistically significant correlation between them (r = 0.753, d.f. = 9, p = 0.007). CONCLUSION: The historical background is very important to attitude and practice regarding marriages between relatives.  相似文献   
905.
Ciprofloxacin metal co mplexes with general for mula [M(CPF)2]X2·nH2O [M = Zn(II), Cd(II), and Hg(II)] have been synthesised and characterized using elemental analysis (CHN), spectroscopic (UV-Vis, IR, MS, and 1H NMR) and ther mogravimetric (TG and DTA) data. Using the Coats-Redfern and Horowitz-Metzeger methods, kinetic analysis of the thermogravimetric data had been performed.  相似文献   
906.
The adsorption of Fe(III) onto glycine-modified chitosan (G@Chs) resin has been investigated. The parameters studied include the effects of pH, contact time, and initial metal ion concentrations by batch method. The optimal pH for the adsorption of Fe(III) was found to be 2.5. The results obtained from equilibrium adsorption studies are fitted in various adsorption models such as Langmuir and Freundlich, and each model parameter were evaluated. Kinetics and thermodynamic parameters of the adsorption process were also investigated. The maximum uptake was found to be 0.9 mmol g?1 at 25°C.  相似文献   
907.
Neurotensin receptors are overexpressed in several human tumors and can be targets for tumors diagnosis and therapy. In this study, a new neurotensin analogue was labeled with 99mTc via HYNIC and tricine/EDDA as coligands and investigated further. [HYNIC0, Gly7, Lys9, d-Tyr11]-Neurotensin (7–13) was synthesized using a standard Fmoc strategy. Labeling with 99mTc was performed at 100 °C for 10 min and radiochemical analysis involved ITLC and HPLC methods. The stability of radiopeptide was checked in the presence of humane serum at 37 °C up to 24 h. The receptor bound internalization and externalization rates were studied in neurotensin receptor expressing HT-29 cells. Biodistribution of radiopeptide was studied in nude mice bearing HT-29 tumor. Labeling yield of 98.6 ± 0.54 % (n = 3) was obtained corresponding to a specific activity of 81 MBq/nmol. Peptide conjugate showed good stability in the presence of human serum. The radioligand showed specific internalization into HT-29 cells (12.43 ± 0.52 % at 4 h). In biodistribution studies, a receptor-specific uptake was observed in neurotensin receptor positive organs so that after 1 h the uptakes in mouse intestine and tumor were 0.87 ± 0.16 and 0.63 ± 0.12 % ID/g respectively.  相似文献   
908.
Solvent‐free synthesis of 3‐substituted indole derivatives by a one‐pot three‐component coupling reaction between aldehyde, N‐alkyl aniline and indole by Fe(HSO4)3 catalyzed is described. The noticeable features of this protocol are the simplicity of the procedure, easy synthesized, recyclable and inexpensive catalyst, no organic solvent and high yields in relatively short reaction times.  相似文献   
909.
Quinazoline derivatives posses many types of biological activities and have recently been reported to show substantial antitumor activity in vitro and/or in vivo. There is a variety of mechanisms for their anticancer activity. The present work reports the possible utility of methyl anthranilate in the synthesis of some new quinazoline derivatives, bearing a substituted sulfonamide moiety. All the newly synthesized compounds were evaluated for their in vitro anticancer activity against human liver cancer cell line, using doxorubicin as a reference drug. In addition, the most active compounds 14 and 15 were selected and evaluated for their ability to enhance the cell killing effect of γ‐radiation.  相似文献   
910.

We report on a new sorbent for preconcentration of cadmium and lead ions that is based on triazine-functionalized magnetite nanoparticles that were prepared by direct silylation of magnetic nanoparticles with 3-aminopropyltriethoxysilane-2,4-bis(3,5-dimethylpyrazol)-triazine. The sorbent was characterized by IR spectroscopy, X-ray powder diffraction, scanning electron microscopy, thermal and elemental analysis. The sorbent was applied to the preconcentration of lead and cadmium ions which then were quantified by FAAS. The effects of sample pH value, extraction time, of type, concentration and volume of eluent, and of elution time were optimized. The limits of detection are 0.7 ng mL−1 for Pb(II) ion and 0.01 ng mL−1 for Cd(II). The effects of potentially interfering ions often found in real samples on the recovery in the determination of cadmium and lead ions in real samples were also investigated. The accuracy of the method was confirmed by analyzing the certified reference materials NIST 1571 (orchard leaves) and NIST 1572 (citrus leaves). Finally, the method was successfully applied to the determination of cadmium and lead ions in some fruit samples.

We report on a new sorbent for preconcentration of cadmium and lead ions that is based on triazine-functionalized magnetite nanoparticles. After optimization of the preconcentration step the method was successfully applied to the determination of cadmium and lead ions in some fruit samples

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